Characteristics of CMC
Sodium carboxymethyl cellulose (CMC) is a water-soluble polymer derived from cellulose, a natural polymer found in plant cell walls. Here are some key characteristics of CMC:
- Water solubility: CMC is highly soluble in water and other aqueous solutions, forming clear or slightly turbid solutions.
- Viscosity: CMC can form highly viscous solutions, depending on the degree of substitution, molecular weight, and concentration. It is commonly used as a thickener and rheology modifier in various applications.
- pH stability: CMC is stable over a wide range of pH values, typically from pH 2 to 12. It can maintain its thickening and stabilizing properties in acidic, neutral, and alkaline conditions.
- Ionic strength sensitivity: CMC can be affected by the ionic strength of the solution. It can form weaker gels or lose its thickening properties in high-salt conditions.
- Hygroscopicity: CMC is hygroscopic, meaning it can absorb moisture from the environment. This property can affect its handling, storage, and performance in certain applications.
- Film-forming properties: CMC can form flexible and transparent films when it dries. It can be used as a coating material or a binder in various applications.
- Biodegradability: CMC is biodegradable and environmentally friendly. It can be degraded by enzymes produced by microorganisms in soil or water.
Overall, sodium carboxymethyl cellulose is a versatile polymer with a range of properties that make it useful in various applications, such as food, pharmaceuticals, personal care, and industrial products.